Apparatus of this kind has been disclosed in published British application No. 2 042 599 of Platt Saco Lowell and similar apparatus has been disclosed in various patents and patent applications by Barmag Barmer Maschinenfabrik AG, Dr. Ernst Fehrer and Vyzkumny Ustav Bavlnarsky. None of these apparatus has yet reached fully successful commercial exploitation. Neither Barmag nor Fehrer have concerned themselves with the problems of fibres remaining in the yarn formation area at an end break, possibly because they have not in their apparatus had the small tolerances and gaps necessary in this area to achieve optimum spinning performance and to reduce air losses. Vyzkumny in their U.S. Pat. No. 4,168,601 disclose an arrangement which also does not have the necessary small gaps and tolerances; but in this arrangement an inner cylindrical roller can be moved axially away from co-operation with the inner surface of an outer roller to allow cleaning of any material remaining in the spinning area at a stoppage and to perform the piecing up function. In this apparatus the spinning area is very large in comparison with the diameter of a yarn and hence there is no need for consideration of problems concerning excess material in that area during operation. The provisions for cleaning this form of apparatus would therefore be adequate to allow proper cleaning of the area although the structure is extremely cumbersome and therefore time consuming and also expensive to manufacture. It is also necessary to stop the motion of the surfaces.
In published British application No. 2 042 599 (particularly in FIG. 2) it is disclosed that one of the bodies can be moved away from the other and from the fibre feed duct, but this is only for purposes of adjustment of the small gaps between these parts for optimisation of the spinning conditions. Careful setting of the gap is necessary for any movement of the movable body in view of the very small tolerances necessary and when set the bodies and the feed duct are for all other purposes fixed.